U.S. patent application number 10/875208 was filed with the patent office on 2004-11-18 for remote control system for a vehicle.
This patent application is currently assigned to HONDA GIKEN KOGYO KABUSHIKI KAISHA. Invention is credited to Asakura, Suguru, Nagai, Akira, Nozawa, Munehisa, Watarai, Sadanori, Yoshimura, Kentaro.
Application Number | 20040227656 10/875208 |
Document ID | / |
Family ID | 16823245 |
Filed Date | 2004-11-18 |
United States Patent
Application |
20040227656 |
Kind Code |
A1 |
Asakura, Suguru ; et
al. |
November 18, 2004 |
Remote control system for a vehicle
Abstract
A remote control system for precisely identifying a distance
from the vehicle to an entry key and favorably controlling a
vehicle-mounted device such as a door corresponding to the
distance. The system comprises a transmitter transmitting different
types of response demand signals within a predetermined
communication area outside the vehicle, a vehicle mounted receiver
for receiving a response signal released from a portable
transmitter/receiver in response to the reception of the response
demand signal, a controller controlling the vehicle mounted device
corresponding to the reception of the response signal by the
vehicle mounted receiver. Locking and/or unlocking door(s) of the
vehicle are controlled on the basis of whether or not the receiver
receives the response signal to a response demand signal other than
one having the largest communication area.
Inventors: |
Asakura, Suguru; (Saitama,
JP) ; Nagai, Akira; (Saitama, JP) ; Yoshimura,
Kentaro; (Saitama, JP) ; Nozawa, Munehisa;
(Saitama, JP) ; Watarai, Sadanori; (Miyazaki,
JP) |
Correspondence
Address: |
WESTERMAN, HATTORI, DANIELS & ADRIAN, LLP
1250 CONNECTICUT AVENUE, NW
SUITE 700
WASHINGTON
DC
20036
US
|
Assignee: |
HONDA GIKEN KOGYO KABUSHIKI
KAISHA
Tokyo
JP
HONDALOCK MFG. CO., LTD.
Miyazaki
JP
|
Family ID: |
16823245 |
Appl. No.: |
10/875208 |
Filed: |
June 25, 2004 |
Related U.S. Patent Documents
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Application
Number |
Filing Date |
Patent Number |
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10875208 |
Jun 25, 2004 |
|
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|
09612315 |
Jul 7, 2000 |
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6778065 |
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Current U.S.
Class: |
341/176 |
Current CPC
Class: |
B60R 25/245 20130101;
G07C 2209/63 20130101; G07C 9/00309 20130101 |
Class at
Publication: |
341/176 |
International
Class: |
H04L 017/02; G08C
019/12 |
Foreign Application Data
Date |
Code |
Application Number |
Aug 9, 1999 |
JP |
11-225049 |
Claims
1 (Canceled).
2: A remote control system for a vehicle comprising: a transmitter
mounted on the vehicle for transmitting a response demand signal
receivable within a predetermined range outside the vehicle; a
portable transmitter/receiver for sending back a response signal in
response to reception of the response demand signal; a receiver
mounted on the vehicle for receiving the response signal sent back
from the portable transmitter/receiver; and a controlling means for
controlling vehicle-mounted components responding whether the
receiver receives the response signal or not, said transmitter
arranged to transmit a plurality of response demand signals
receivable within different corresponding predetermined ranges,
said controlling means arranged to identify that the portable
transmitter/receiver exists within the largest predetermined
receivable range and to make the transmitter transmit another
response demand signal receivable within a predetermined range
which is smaller than the largest size of the predetermined range
in addition to the response demand signal receivable in the largest
size of the predetermined range when a response signal is received
by the receiver, which response signal corresponds to reception of
particular response demand signal being receivable within the
largest predetermined receivable range and, to control at least
either unlocking or locking of a door(s) of the vehicle depending
on whether a response signal is received or not by the receiver,
which response signal corresponds to reception of the other
response demand signal than a particular one being receivable
within the largest predetermined receivable range.
3-5 (Canceled).
6: A remote control system for a vehicle according to claim 2,
further comprising a disembarkation detecting means for detecting
the disembarkation of a user, wherein when the disembarkation of
the user is detected, a response demand signal receivable within
the smallest size of the predetermined range is transmitted from
the transmitter, and when the response signal showing reception of
the response demand signal receivable in the smallest size of the
predetermined range is no more received by the receiver mounted on
the vehicle, a second response demand signal receivable within the
second smallest size of the predetermined range is begun to be
transmitted from the transmitter in addition to the response demand
signal receivable in the smallest size of the predetermined range
and, in a similar manner, a response demand signal receivable
within a relatively larger size of the predetermined range is
transmitted in sequence from the transmitter.
7: A remote control system for a vehicle according to claim 2
wherein when the response signal to the response demand signal
receivable within the largest size of the predetermined range is
received after it is not received by the receiver mounted on the
vehicle, the response demand signal receivable within second
largest size of the predetermined range is transmitted from the
transmitter in addition to the response demand signal receivable
within the largest predetermined range and then a response demand
signal receivable within a relatively smaller size of the
predetermined range is transmitted in sequence from the
transmitter.
8: A remote control system for a vehicle according to claim 2
wherein further comprising an embarkation detecting means for
detecting the embarkation of a user, wherein when the embarkation
of the user is detected by the embarkation detecting means, a
response demand signal receivable within the vehicle is transmitted
from the transmitter, and when the response signal to the response
demand signal receivable inside the vehicle is received by the
receiver, action of an engine is enabled.
9-12 (Canceled).
Description
BACKGROUND OF THE INVENTION
[0001] 1. Field of the Invention
[0002] The present invention relates to a remote control system for
a vehicle which can automatically lock and unlock the door(s) of a
vehicle in wireless communication and more particularly to a remote
control system for a vehicle which can automatically lock the
door(s) of a vehicle when a user (driver) who carries with him an
electronic or entry key (with a portable transmitter/receiver)
which includes an identification code assigned to the vehicle walks
away a predetermined distance from the vehicle and automatically
unlock the same when the user comes back to the distance.
[0003] 2. Description of the Related Art
[0004] Lock/unlock remote-control systems for vehicle doors are
known having a so-called, "welcome function". In the systems, every
user (driver) of a vehicle owns an entry key (with a portable
transmitter/receiver) which upon receiving a response demand signal
that is transmitted from a transmitter installed in the vehicle and
is receivable within a predetermined range about the vehicle (which
may be referred to as "having a predetermined communication area"
hereinafter), can transmit a response signal carrying a unique
identification code assigned in advance to each vehicle. When the
user walks away from the predetermined range of the vehicle and its
entry key is disabled to receive the response demand signal and
thus to transmit back the response signal, the door of the vehicle
is automatically locked. When the entry key moves into the
predetermined range and its response demand signal is received by
the transmitter/receiver which then responses thereto to send back
a response signal, the door is automatically unlocked.
[0005] For example, some of such conventional "welcome function"
based lock/unlock remote-control systems for vehicle doors are
disclosed in Japanese Patent Laid-open Publications
(Heisei)5-106376 and (Heisei)10-25939 in which a transmitter
mounted on a vehicle is provided for intermittently transmitting a
response demand signal having a predetermined communication area
and, when receiving a signal responding to the response demand
signal from an entry key which is carried by the user of a vehicle
and moves into the predetermined communication area, examining
whether the response signal is valid (regular) or not (welcome code
examination). When the response signal has been examined to be
valid, the door(s) of the vehicle is automatically unlocked. On the
contrary, when the response signal is not valid or when the entry
key stays out of the predetermined communication area and the
vehicle-mounted transmitter receives no response signal, the door
remains locked.
[0006] Accordingly, when the user of the vehicle carrying the entry
key simply walks away from the predetermined range of the vehicle,
the door of the vehicle can automatically be locked without paying
any attention to or operating the entry key. When the user comes
into the range, the door can automatically be unlocked. This
requires no boresome actions of unlocking the door for riding the
vehicle as well as contributes to the prevention of failing to lock
door(s), and of vehicle theft.
[0007] The conventional systems have some advantages, particularly
once the communication area is preset to a smaller size (for
example, one meter in radius), the systematic locking of the door
can easily be confirmed after getting off the vehicle, the power
consumption for transmitting signals can be as small as not hostile
to a battery, and the ID code (uniquely assigned to a vehicle) can
hardly be intercepted by any other parties. The locking of the door
may be easily confirmed by auditorily and visually perceiving the
sound of a door locking mechanism and the shift of an inside door
lock knob to the lock position.
[0008] Another conventional system disclosed in Japanese Patent
Laid-open Publication (Heisei)10-153025 is provided in which a
transmission antenna for detecting the approaching of an object
into a middle-sized area around a vehicle is mounted on the vehicle
in addition to an antenna for transmitting the response demand
signal. Upon detecting the approaching of the object or a driver
into the middle-sized area, the vehicle releases the response
demand signal with a small-sized predetermined communication area
and, when receiving a response signal to the response demand signal
from the entry key of the right driver, unlock the door. Also, a
second transmitting means having a greater communication area is
provided for locking the door. The door is thus locked when the
communication to the entry key with the second transmitting means
is disabled.
[0009] According to the conventional systems, when the
communication area for the response demand signal is set to be wide
enough to detect the driver approaching into the area of the
vehicle at an earlier occasion, the door(s) can be unlocked
positively before the driver reaches the vehicle. This eliminates
the need of the door being unlocked by the driver or user and
provides the ease of getting in the vehicle with operating only a
door outer handle, hence improving the utility.
[0010] However, as the communication area is wide, the locking of
the door will be carried out only when the user departs further
from the vehicle, hence causing the user to confirm the door
locking (through listening to the sound of the door locking
mechanism or viewing the shift of the inside door lock knob to the
lock position) with much difficulty. Also, while the user with the
entry key walks about or pursues a job (e.g. ordering throughout
the trunk room), the door locking is not performed and it may fail
to protect articles in the vehicle from a thief.
[0011] In particular, when the user with the entry key is departing
from the vehicle, its back is often turned to the vehicle. The
wider the predetermined communication area, the longer the period
of the door remaining unlocked is extended and thus the higher the
risk of being thieved will be increased. Also, the wider
communication area requires a higher level of power for
transmitting the response demand signal and the power consumption
will be soared up drawing more power from the battery.
[0012] For compensation, a modification is proposed such as
disclosed in Japanese Patent Laid-open Publication (Heisei)
10-25939, where the communication area is reduced (about one meter
in radius) allowing the response demand signal to be not received
in a shorter distance from the door thus to lock the door. This
permits the door locking to be easily confirmed, the ID code (ID
number) to be hardly intercepted, and the power for signal
transmission to be minimized, hence lowering the power
consumption.
[0013] However, the above modification will hardly ensure the
unlocking of the door. It is common in the art for minimizing the
power consumption for transmitting the response demand signal that
the response demand signal from the vehicle is usually transmitted
intermittently. With the wider communication area, the user moving
in the wider area is able to communicate with the vehicle, even if
the response demand signal is transmitted with longer intermission
period. Accordingly, the door is surely unlocked before the user
arrives at the vehicle.
[0014] With the smaller communication area, however, when the user
rushes to the vehicle in less time through the communication area,
the communication between the vehicle-mounted transmitter and the
entry key may not be completed until the user arrives at the
vehicle. This causes the door to remain locked and its door outer
handle may have to be operated a number of times without success.
As a result, the entry key system will be lost in commercial value.
As a further modification, the period of the intermittent
transmission of the response demand signal may be shortened. This
will however increase the power consumption and cause more power be
drawn from the battery.
[0015] On the other hand, the conventional system disclosed in the
above-mentioned Japanese Patent Laid-open Publication
(Heisei)10-153025 allows the power for transmitting the response
demand signal to be possibly decreased, but it requires the extra
transmission antenna for detecting the invading of an object, hence
increasing the complexity of the overall arrangement and thus the
cost of the system. Also, the power consumption will be increased
by the additional equipment. Moreover, the above system transmits
the response demand signal even when any other personal or creature
than the right entry key (user) advances close to the vehicle,
hence requiring more improvement for the power consumption. Since
the communication area is too small to examine whether the entry
key is right or not as required before accepting the unlocking, the
door may remain not unlocked when the user or driver rushes to and
arrives at the vehicle. This will result in the misconduct of the
automatic unlocking function.
SUMMARY OF THE INVENTION
[0016] An object of the present invention is to provide a remote
control system for a vehicle which can predictably control a
vehicle mounted device such as a door of the vehicle corresponding
to the distance from the vehicle to an entry key.
[0017] As a first feature of the present invention, the remote
control system for a vehicle comprises: a transmitter mounted on
the vehicle for transmitting a plurality of response demand signals
which are receivable within different sizes of a predetermined
range outside the vehicle; a portable transmitter/receiver for
receiving the response demand signals and sending back a response
signal; a receiver mounted on the vehicle for receiving the
response signal sent back from the portable transmitter/receiver;
and a controlling means for controlling vehicle-mounted components
corresponding to the reception of the response signal by the
receiver, wherein said controlling means arranged to control at
least either unlocking or locking of the door(s) of the vehicle
depending on whether the response signal to a type of the response
demand signal other than a particular response demand signal being
receivable in the largest size of the predetermined range is
received or not by the receiver.
[0018] As a second feature of the present invention, the
transmitter intermittently transmits different types of the
response demand signals receivable within corresponding sizes of
the predetermined range, and the controlling means identifies a
particular predetermined range where the portable
transmitter/receiver is located on the basis of the interval
between receptions of the response signals and controls the
vehicle-mounted components in a predetermined mode, corresponding
to the size of the predetermined range where the
transmitter/receiver is located.
[0019] As a third feature of the present invention, various types
of response demand signals are intermittently transmitted at
different intervals such that the transmission of one type of the
response demand signal receivable within a smaller predetermined
range is transmitted at least once between two adjacent
transmitting timings of another type of the response demand signal
receivable in a wider predetermined range.
[0020] As a fourth feature of the present invention, the response
signals sent back from the portable transmitter/receiver are
discriminatable one another according to which size of the
predetermined range of the respond demand signal that the respond
signals respond to.
[0021] As a fifth feature of the present invention, when the
disembarkation of the user is detected and the user is departing
from the vehicle, a type of the response demand signal receivable
within the smallest size of the predetermined range is transmitted
from the transmitter, and when the response signal showing
reception of the response demand signal receivable in the smallest
size of the predetermined range is no more received by the receiver
mounted on the vehicle, another type of the response demand signal
receivable within the second smallest size of the predetermined
range is begun to be transmitted from the transmitter and, in a
similar manner, when the response signal to a type of the response
demand signal receivable in a relatively smaller size of the
predetermined range is no more received by the receiver mounted on
the vehicle, a further type of the response demand signal
receivable within a relatively larger size of the predetermined
range is begun to be transmitted in sequence from the
transmitter.
[0022] As a sixth feature of the present invention, when the entry
key is approaching to the vehicle and the response signal to the
type of the response demand signal receivable within the largest
size of the predetermined range is first received by the receiver
mounted on the vehicle, the response demand signal receivable
within second largest size of the predetermined range is
transmitted from the transmitter and then a response demand signal
receivable within a relatively smaller size of the predetermined
range is transmitted in sequence from the transmitter.
[0023] As a seventh feature of the present invention, when the
embarkation of the user is detected by the embarkation detecting
means, a type of the response demand signal receivable within the
vehicle is transmitted from the transmitter.
[0024] According to the first feature of the present invention, the
distance from the vehicle to the user carrying the portable
transmitter/receiver (entry key) can precisely be identified thus
to control the vehicle mounted device such as the door(s) at an
optimum length of the distance, hence improving the utility of
controlling the vehicle mounted device such as unlocking and
locking the door is compatible with the anti-thief function.
[0025] According to the second feature of the present invention,
the distance range from the vehicle to the user carrying the
portable transmitter/receiver can be identified on the basis of the
interval between receiving timings of the sent-back response signal
on the vehicle even if characteristic codes included in the
response signals are not different each other, which response
signals are sent back from the portable transmitter/receiver that
responds to a plurality types of the response demand signal
receivable within their respective sizes of the predetermined
ranges which are different each other. Hence, the vehicle mounted
device can favorably be controlled depending on the distance as
well as the construction of the transmitter of the portable
transmitter/receiver and the code identifying action of the
controlling means on the vehicle can significantly be
simplified.
[0026] According to the third feature of the present invention, the
response signal is also intermittently released from the portable
transmitter/receiver, thus providing the same effects and
advantages as described just above.
[0027] According to the fourth feature of the present invention, as
the response signals released from the portable
transmitter/receiver in response to reception of the response
demand signal are different each other based on the different sizes
of the receivable ranges of the demand signals, the distance from
the vehicle to the portable transmitter/receiver can be identified
only from the response signal received and the optimum control of
the device mounted on the vehicle can be performed in accordance
with the distance.
[0028] According to the fifth and sixth features of the present
invention, at the disembarkation of the user, as the portable
transmitter/receiver carried by the user departs far from the
vehicle, the transmission of the response demand signal receivable
in a wider size of the predetermined range is executed in sequence
and the transmission of the response demand signal receivable in a
smaller size of the predetermine range is canceled. As the potable
transmitter/receiver comes from far towards the vehicle, on the
other hand, the transmission of the response demand signal with a
relatively smaller predetermined receivable range is not executed
before the response signal responding to the response demand signal
with a relatively larger predetermined receivable range is received
by the vehicle.
[0029] More particularly, while the portable transmitter/receiver
is out of the largest predetermined receivable range, the response
demand signal receivable in the largest predetermined range only is
transmitted. Only when the response signal responding to the
response demand signal receivable in the largest predetermined
range is received by the vehicle, the transmission of the response
demand signal being receivable in a smaller size of the
predetermine range and used for actually controlling the unlocking
and locking of the door is executed. Therefore, the transmission of
the response demand signal is minimized hence reducing the
consumption of a power from a battery equipped on the vehicle.
[0030] According to the seventh feature of the present invention,
the user carrying the portable transmitter/receiver in the vehicle
can readily be acknowledged, and the vehicle mounted device in the
vehicle is controlled on the basis of the response signal from the
portable transmitter/receiver responding to a particular type of
the response demand signal receivable within the vehicle, hence
improving the anti-thief function.
BRIEF DESCRIPTION OF THE DRAWINGS
[0031] FIG. 1 is a block diagram showing a structure of the first
embodiment of the present invention;
[0032] FIG. 2 is a timing chart illustrating the automatic
unlocking action of a door in the first embodiment of the present
invention when the driver carrying the entry key moves to the
vehicle and embarks;
[0033] FIG. 3 is a timing chart illustrating the automatic locking
action of the door in the first embodiment of the present invention
when the driver disembarks and the entry key departs from the
vehicle;
[0034] FIG. 4 is a part of the main flowchart showing an action of
the first embodiment of the present invention;
[0035] FIG. 5 is the remaining part of the main flowchart showing
an action of the first embodiment of the present invention;
[0036] FIG. 6 is a flowchart showing the transmission of a response
demand signal with timer interruption in the first embodiment of
the present invention;
[0037] FIG. 7 is a flowchart showing a refresh 1 process in FIG.
4;
[0038] FIG. 8 is a flowchart showing a refresh 2 process in FIG.
4;
[0039] FIG. 9 is a flowchart showing a part of a welcome process in
FIG. 4;
[0040] FIG. 10 is a flowchart showing the remaining part of the
welcome process in FIG. 4;
[0041] FIG. 11 is a flowchart showing an immobilizing checking
process in FIG. 4;
[0042] FIG. 12 is a flowchart showing the transmission of an I
response demand signal with timer interruption in the first
embodiment of the present invention;
[0043] FIG. 13 is a schematic view showing the relation between the
control operations and the distance from the vehicle to the entry
key in the first embodiment of the present invention;
[0044] FIG. 14 is a schematic view showing the relation between the
control operations and the distance from the vehicle to the entry
key in another embodiment of the present invention;
[0045] FIG. 15 is a diagram showing an exemplary format of the
response demand signals preferably applicable to the present
invention;
[0046] FIG. 16 is a diagram showing an exemplary format of the
response signal for immobilizing operation preferably applicable to
the present invention;
[0047] FIGS. 17 and 18 are main flowcharts showing the action of a
further embodiment of the present invention as combined;
[0048] FIG. 19 is a flowchart showing a part of a welcome process
in FIG. 17;
[0049] FIG. 20 is a flowchart showing the transmission of the
response demand signal with timer interruption in a further
embodiment of the present invention;
[0050] FIGS. 21A and 21B are a timing chart showing the
transmission of the response demand signal in a still further
embodiment of the present invention as combined;
[0051] FIG. 22 is a timing chart illustrating the automatic locking
action of the door in the still further embodiment of the present
invention when the driver disembarks and the entry key departs from
the vehicle;
[0052] FIG. 23 is a timing-chart illustrating the automatic
unlocking action of a door in the still further embodiment of the
present invention when the deriver carrying the entry key moves to
the vehicle and embarks;
[0053] FIGS. 24 and 25 are main flowcharts showing in a combination
the action of the still further embodiment shown in FIGS. 22 and
23; and
[0054] FIG. 26 is a flowchart showing a part of a welcome process
in FIG. 24.
DETAILED DESCRIPTION OF THE PREFERRED EMBODIMENTS
[0055] An entry key system for a vehicle according to first
embodiment of the present invention will be describe in more detail
referring to the accompanying drawings. Before starting the main
description, some definitions on the flags at 1 of the bit and the
timers employed in the description and the drawings are explained
as listed below.
[0056] AREC=reception of A code;
[0057] ATM=transmission of A response demand signal;
[0058] BCHG=start of examining the shift from small B response
demand signal to large B response demand signal;
[0059] BLTM=transmission of large B response demand signal;
[0060] BREC=reception of B code;
[0061] BSTM=transmission of small B response demand signal;
[0062] I(variable)=the number of consecutive receptions of A
code;
[0063] IMCHK=start of immobilizing checkup;
[0064] IMDONE=finish of immobilizing checkup;
[0065] IMOK=result of immobilizing checkup;
[0066] m(variable)=setting in timer T-OUT;
[0067] MOD(n,m)=remainder of n/m;
[0068] n(variable)=setting for the kind of response demand signals
to be transmitted;
[0069] OUT=the entry key is out of communication area for A
response demand signal;
[0070] RCHK=timer T-OUT has started for examining the entry key is
not near about vehicle;
[0071] RF1/2=finish of refresh procedure 1, 2, respectively;
[0072] T-BCHG=timer for setting exchange of B response demand
signals;
[0073] T-IMCHK=timer setting time for immobilizing checkup;
[0074] T-OUT=timer setting time for judging that the entry key is
out of communication area for A response demand signal;
[0075] T-WR1/2=first and second timers each for measuring intervals
of signal reception;
[0076] timer interrupt permission bit for response demand
signal=timer interruption permission for transmission of response
demand signal.
[0077] A first embodiment of the present invention will be
described in the form of a remote control system for a vehicle
referring to the block diagram of FIG. 1.
[0078] A smart entry unit 1 comprises a power supply circuit 2 such
as a battery equipped on the vehicle, an input/output circuit 3
connected to LF (low frequency) transmitter circuits 9a to 9c, a
bus communication circuit 4 connected by a communication line 32 to
an ignition SW unit 10 which will be described later, a memory
circuit 5, an MOSFET circuit 6, an input circuit 7, and a CPU 8
connected to above-mentioned circuit components for controlling
their actions. The CPU 8 is further connected to an RF receiver
circuit 9f. The input circuit 7 is connected to a manual SW 7a for
setting the system to a manual mode in which it is responsive to
only a manual code derived by manual operation from an entry key 50
which is described later, as well as a parking SW 7b, four door SWs
7c, an engine hood SW 7d, a door key cylinder SW 7e, and so on.
[0079] The entry key 50 which is usually carried and manipulated by
a driver or user of the vehicle comprises an RF circuit 51 for
transmitting an RF signal from an antenna, an alarm/display 52 such
as a buzzer, a rectifier trigger (TRIG) circuit 53 for processing
LF signals received which are transmitted from the LF transmitter
circuits 9a to 9c, a CPU 54, a battery 55, manual switches 56 and
57 for transmitting manual codes for manually locking and unlocking
the door, and a switch 58 for allowing/prohibiting the manual
operation. The switches 56 and 57 may be modified in to a single
switch for repeating alternately the lock and unlock actions.
[0080] The ignition SW unit 10 comprises a bus communication
circuit 11 for exchanging signals via the communication line 32
with the smart entry unit 1, a power supply circuit 12, a memory
circuit 13, an immobilizing (anti-thief functioning) antenna 14, a
low frequency (LF) transmitter/receiver circuit 15, a key SW 16 for
detecting the insertion/extraction of a key, an ignition (IGN) SW
17, an IGN position detector 18 for detecting the contact position
of the IGN SW 17, a motor 19 for actuating a rotary contact of the
IGN SW 17, a motor driver 20 for driving the motor 19, an auxiliary
(or emergency) key 21 which is inserted and extracted to and from
the key cylinder, an interlock ACT (actuator) 22 for prohibiting
the removal (or extraction) of the auxiliary key 21, an ACT driver
23 for driving the interlock ACT 22, and a CPU 24 for controlling
the actions of the above-mentioned components. The CPU 24 is also
connected to a quick start SW 31 for starting the engine.
[0081] The operation of the smart entry unit 1 and the entry key 50
will schematically be described referring to the timing charts of
FIGS. 2 and 3 and the schematic view of FIG. 13. FIGS. 2 and 3
illustrate the welcome function in which the door of the vehicle is
unlocked and locked in response to the detection of the user
carrying the entry key 50 (who may hence be simply referred to
"entry key" hereinafter) coming close to the vehicle 1 for boarding
and leaving from the vehicle 1 after getting off, respectively. In
these figures, the height of the bars of the response demand
signals represents the intensity of the signals thus indicating the
size of the communication area (receivable range).
[0082] When the entry key is outside of and distanced significantly
from the vehicle of which the door remains locked in a disembark or
parking mode, an A response demand signal (of e.g. 100 kHz) shown
at the left side end in FIG. 2 is transmitted from the vehicle at
equal intervals of a first predetermined time (y seconds) and with
an intensity corresponding to the maximum communication area (for
example, 4 to 5 meters in radius) denoted by A in FIG. 13. As the
driver carrying the entry key moves into the communication area A
for the A response demand signal, the entry key receives the A
response demand signal at the moment t1 and transmits a send-back
signal or a response signal responding to the A response demand
signal which includes an A code and may be referred to as "A code"
hereinafter. The format of the response signal will be explained
later in more detail referring to FIG. 15.
[0083] The vehicle, when receiving the response signal and judging
that the response signal received is valid, releases a large-area B
response demand signal (e.g. of 300 kHz and having a
one-meter-radius communication area denoted by B (large) in FIG.
13) from t2 at equal intervals of a second predetermined time (x
seconds). It is assumed y>x or more specifically, y=3x in this
embodiment. Upon receiving the B large response demand signal at
t3, the entry key 50 releases a response signal which includes a B
code and may be referred to as a "B code" hereinafter. When it is
judged that the response signal including the B code is valid, the
door of the vehicle is unlocked.
[0084] As the door is opened at t4 (door SW is on) and then closed
at t5, it is determined that the driver has embarked and an I
(immobilizing) response demand signal designated its communication
area as in the interior of the vehicle is transmitted. When the
entry key then releases a response signal to the I response demand
signal which include an I code (immobilizing code), the vehicle
carries out immobilizing checkup (immobilizing code examination)
for deciding whether the I code received is valid or not. When the
I code is valid, the transmission of the I response demand signal
is canceled and an FI-ECU 33 is switched at t6 into the engine
enabling mode.
[0085] Then, upon the ignition SW (IGN SW) being turned to the ON
position at t7, the transmission of both the A and B response
demand signals is stopped and simultaneously a refresh 2 process is
commenced as will be described later. The transmission of the A and
B response demand signals may be stopped, instead, upon judging
that the I code is valid or in response to the on/off action of the
door switch triggered by the opening and closing of the door.
[0086] The movement of the vehicle 1 is stopped and then as the IGN
SW is turned from the ON position to the ACC position at t1 as
shown in the left end of FIG. 3, the FI-ECU 33 is switched to the
engine disabling mode. When the door SW is shifted from the OFF
position (door closed) to the ON position (door opening) at t2 in
the door unlock mode, it is judged that the driver is about to
disembark and the transmission of a B small response demand signal
(e.g. of 300 kHz having substantially a 0.5-meter-radius
communication area denoted by B (small) in FIG. 13) is then
commenced. This is followed by transmitting the B small response
demand signal at equal intervals of the second predetermined time
(x seconds) from the vehicle. Then, as the door SW is shifted from
the ON position to the OFF position (door closed) at t3, the I
response demand signal is transmitted at the predetermined
intervals.
[0087] When the entry key is disembarked, it enables to receive not
the I response demand signal but the B small response demand
signal. Then a response signal to the B small response demand
signal including the B code is released. When the response signal
including the B code is receive and is judged to be valid at t4,
the A response demand signal is commenced to be transmitted while
the transmission of the I response demand signal is stopped. The
entry key continues to release the A and B codes while receiving
both the A and B small response demand signals.
[0088] As the driver with the entry key moves away from the vehicle
and steps out from the B small area shown in FIG. 13, it is
disabled to receive the B small response demand signal and no
response signal with B code to the B response demand signal shall
be sent back. When the B code is not received by the vehicle after
a predetermined period from the reception of the A code (at t5 in
FIG. 3), the B response demand signal is switched from the B small
signal to the B large signal. As the B code is no more received
after the predetermined period while the A code is received and its
welcome code examination is executed (i.e. in this embodiment, only
the A code is continuously received but the B code has not been
received in y seconds), the door is then locked at t7 when the
final A code is examined to be valid.
[0089] After t8 when the setting (m seconds) of the T-OUT timer has
elapsed since the entry key is far enough away from the vehicle not
to receive the A response demand signal and thus not to send back
the A code, the intermittent transmission of only the A response
demand signal at the intervals of y seconds is maintained.
Alternatively, as denoted by the dotted line in FIG. 3, the door
may be locked at t5 when the A code is received just after the
reception of the B code at the estimated moment is not
executed.
[0090] The operation of the smart entry unit 1 will now be
described schematically referring to the flowcharts of FIGS. 4 and
5.
[0091] Upon energized, the system is initialized in its entirety
(Step S1). At Step S2, it is examined whether the ignition switch
(referred to an IGN SW hereinafter) is turned on or not. When the
IGN SW is turned off by the driver to stop the vehicle at t1 in
FIG. 3, the procedure goes to Step S3 where the refresh 1 process,
i.e. the initialization of flags for the (anti-thief) immobilizing
system, is carried out. This process at Step S3 will be explained
later in more detail referring to FIG. 7.
[0092] This is followed by Step S5 where it is examined whether the
door is unlocked or not. At Step S6, it is examined whether or not
the door SW is turned from the ON position to the OFF position
(i.e. whether the opened door of the vehicle is closed or not). As
it is judged "NO" at Step S6 while the door is opened for
disembarkation, the procedure jumps to Step S9 where it is examined
whether or not the manual SW7a is turned on for shifting the system
to the manual mode where the door can be unlocked and locked using
the manual switch. In normal, the manual SW 7a remains turned off
(i.e. the manual mode is not selected) and it is judged "NO". It is
then examined at Step S10 whether or not the door SW is turned from
the OFF position to the ON position (i.e. the closed door is
opened).
[0093] As the door is opened for disembarkation, the door switch is
turned from the OFF position to the ON position and it is judged
"YES" at Step S10. Then, Step S11 follows where it is examined
whether the BREC flag is 1 or not (i.e. the B code is received or
not). In the beginning, the B code is not received and the
procedure advances to Step S12 where the BSTM flag is set to 1 and
the variable n for determining the type of the response demand
signal (A, B small, or B large) is reset to 0.
[0094] Step S12 is a process of selecting the type of the response
demand signal to be transmitted and, as will be explained later,
the B small type having a smaller communication area is set. At
Step S13, the timer interruption permitting bit for enabling the
transmission of the response demand signal is set, i.e. the
transmission of the response demand signal by timer interruption is
enabled.
[0095] Then Step S14 follows where it is examined whether the valid
ID code is received or not. When it is affirmative, it is then
judged at Step S15 what the function code is. More specifically, it
is examined whether received signal is the response signal (A code
or B code) from the entry key 50 or the manual code for the manual
operation. In the beginning, it is judged "NO" at Step S14 and the
procedure moves to Step S15A where it is examined based on the
IMCHK flag whether the immobilizing checkup is finished or not. At
the time, the immobilizing checkup is not performed and the
procedure jumps to Step S30 (in FIG. 5). Similarly, it is judged
"NO" at Step S30 and the procedure goes to Block S41. At Block S41,
the flags for the welcome function are initialized when the code is
not received during a predetermined period of time.
[0096] In fact, it is examined referring to the OUT flag at Step
S31 whether or not the entry key is out of the communication area
for the A response demand signal. In the beginning, it is not
registered (i.e. OUT flag=0) that the entry key is out of the
communication area for the A response demand signal. It is then
examined at Step S32 whether the RCHK flag is 1 or not (i.e. the
T-OUT timer for setting time duration to determine that the entry
key is not adjacent to the vehicle, has been started or not) When
it is judged "NO", the procedure goes to Step S33 where the T-OUT
timer is set to m seconds. It is preferable that m satisfies m
sec>y(=3x) sec.gtoreq.z sec where y is the interval of
transmission (or cycle) of the A response demand signal, x is the
interval of transmission of the B response demand signal, and z is
the interval of transmission of the I (immobilizing) response
demand signal, as shown in FIG. 2. Then, at Step S34, the RCHK flag
is set to 1 for starting the T-OUT timer.
[0097] This is followed by Step S35 where it is examined whether
the T-OUT timer is turned to zero as the setting time of m seconds
has been elapsed. In the beginning, the setting time of m seconds
is not elapsed and thus the procedure returns back to Step S2.
[0098] As the driver disembarks and the door is closed, the door
switch is shifted from the ON position to the OFF position allowing
Step S6 to judge "YES". The procedure thus goes to Step S7 where
the refresh 1 flag is reset to 0. Step S8 follows where the timer
interruption permitting bit for permitting the transmission of the
I response demand signal is initiated to enable the transmission of
the I response demand signal with timer interruption. Then, the
procedure moves to Steps S14, S15A, and S30, and Block S41 and
returns back to Step S2.
[0099] As the entry key 50 is moved out of the vehicle, it receives
the B small response demand signal and sends back the B code. The B
code from the entry key 50 is received by the receiver on the
vehicle and qualified as a valid code and it is then judged "YES"
at Step S14. The procedure thus goes to Step S15 where it is
examined whether or not the signal code received is the manual code
sent from the entry key 50 by the manual switch operation for
locking and unlocking the door. When it is judged "YES", the
procedure advances to Step S16 where the manual operation is
enabled (which is a process to interpret the code issued through
the manual switch operation and will be explained in no more
detail).
[0100] As the received code is the B code carried on a response
signal to the response demand signal at present, it is judged "NO"
at Step S15 and the procedure moves to Step S17 where it is
examined whether the manual SW is turned on or not. When it is
judged "YES" at Step S17, the procedure returns back to Step S2. As
"NO" is given at Step S17, however, the procedure goes to Step S18
where the welcome function process for unlocking and locking the
door in response to the result of the welcome code judgment is
executed.
[0101] Welcome Function Process at Disembarkation
[0102] The welcome process at Step S18 in FIG. 4 will now be
explained in more detail referring to FIGS. 9 and 10. It is assumed
that the driver stops the engine, disembarks, and departs with the
entry key from the vehicle. As described previously, the
disembarkation of the driver is followed by Step S12 (FIG. 4) for
selecting the transmission of the B small response demand signal
and resetting the variable n to 0 and Step S13 for enabling the
transmission of the B response demand signal with timer
interruption. Then, the welcome process is commenced at Step S18 in
response to the reception of the correct B code.
[0103] The welcome process starts with Step S171 where it is
examined whether the signal code received from the entry key is the
A code or not. In the beginning, since the A response demand signal
is not transmitted it is judged "NO", allowing the procedure to
goes to Step S201. When it is judged at Step S201 that the received
code coincides with the right B code, the procedure moves to Step
S202 where the BREC flag representing the reception of the B code
is set to 1 while the number of consecutive receptions of the A
code denoted by I is set to zero. Step S204 follows where the door
is unlocked.
[0104] It is then examined at Step S209 whether the AREC flag is 1
or not. As the A code is not received by now, it is judged "NO".
The procedure hence goes to Step S210 where the ATM flag is set to
1 for enabling the intermittent transmission of the A response
demand signal. At Step S211, the variable n is set to 0. At Step
S212, the timer interruption permitting bit for the I response
demand signal is cleared off to inhibit the transmission of the I
response demand signal. At Step S214, the BCHG flag is set to 0.
While the B code only is received continuously, the above steps are
repeated.
[0105] When the A code is released from the entry key in response
to the reception of the A response demand signal and received by
the vehicle, it is judged "YES" at Step S171. The procedure then
goes to Step S172 where the AREC flag is set to 1 while the OUT
flag and the RCHK flag are turned to 0 to register that the entry
key 50 is within the communication area for the A response demand
signal and reset the T-OUT timer. At next Step S173, the variable I
indicating the number of consecutive reception of the A code is
increased by 1 for updating (I is thus turned to 1). It is then
examined at Step S174 whether or not the variable I is turned to 2
(for example). In the beginning, I is not 2 and the procedure jumps
to Step S180.
[0106] It is examined at Step S180 whether the BSTM flag indicating
the selection of the B small response demand signal is 1 or not. As
the BSTM flag is 1 so far, it is judged "YES" and the procedure
moves to Step S181 where it is examined whether the BCHG flag for
causing the B response demand signal being switched from the B
small to the B large is 1 or not. As the BCHG flag is now 0, the
procedure goes to Step S182 for setting the BCHG timer to, for
example, 30 seconds.
[0107] The setting time for the BCHG timer may be determined on the
basis of experiments or actual measurements to a duration enough to
allow the entry key to get away enough from the vehicle and step
out of the communication area for the B large response demand
signal. Then, the procedure moves to Step S184 where the BCHG flag
is shifted to 1. It is then examined at Step S185 whether the BCHG
timer is turned to zero or not. In the beginning, the timer is not
zero and the procedure returns back to Step S2.
[0108] As the entry key steps out of the communication area for the
B small response demand signal (FIG. 13), the B code is no more
received but the A code is continuously received on the vehicle.
Step S171 only of the welcome process repeats judging "YES".
Accordingly, the variable I is updated to 2 at Step S173 and it is
judged "YES" at Step S174. The procedure hence goes to Step S176
for locking the door.
[0109] When the A code is next received from the entry key, the
procedure jumps from S174 to S180 and then from S181 to S185. As it
is judged "NO" at Step S185 before the setting time (for example,
30 seconds) of the BCHG timer elapses, the procedure returns back
to Step S2. When the setting time has elapsed, however, it is
judged "YES" at Step S185.
[0110] As a result, the procedure advances to Step S186 where the
BSTM flag for selecting the B small response demand signal is
turned to 0. At Step S187, the BLTM flag for selecting the B large
response demand signal is turned to 1. Accordingly, the
transmission of the B large response demand signal is initiated by
timer interruption. As the entry key is far enough away the vehicle
and out of the communication area of the B large demand signal at
the time, it is disabled to receive the B large response demand
signal and sends back non of the B code.
[0111] As the entry key departs further from the vehicle, it is
disabled to receive finally the A response demand signal and thus
to release the A code. This causes Step S14 of the procedure to
judge "NO" and the procedure moves via Step S15A shown in FIG. 4 to
Step S30 shown in FIG. 5. Then, Block S41 follows in which the
flags are examined at Steps S31 and S32 before the T-OUT timer is
set to m seconds at Step S33, as described previously. As long as
it is judged "NO" at Step S35, the procedure always restarts from
Step S2.
[0112] When the A code is no more sent back and it is thus judged
"YES" at Step S35 after m seconds of the setting time on the T-OUT
timer, i.e. any sent-back code from the entry key 50 is not
received in a duration of m seconds, as illustrated in the
flowchart of FIG. 5, the procedure moves to Steps S36 to S39 for
initializing the AREC, BREC, BLTM, and BSTM flags to 0 which flags
relate to the welcome process. The procedure then goes to Step S40
where the OUT flag is turned to 1 to register that the entry key 50
is out of the communication area for the A response demand signal.
This is followed by the procedure returning back to Step S2 for
repeating the steps.
[0113] As the BLTM and BSTM flags are set to 0 at the time, the
procedure is after t8 in FIG. 3 and before t1 in FIG. 2 where the
intermittent transmission of only the A response demand signal is
executed. As apparent, the A response demand signal is not received
by the entry key and its response signal carrying the A code is not
sent back.
[0114] Welcome Function Process at Embarkation
[0115] A case of the driver with the entry key 50 approaching and
embarking the vehicle will now be explained. As the entry key moves
from a far enough point where the A response demand signal cannot
be received to a near point within the communication area for the A
response demand signal, it receives the A response demand signal
and sends back the A code in response. When the A code is received
by the vehicle, it is judged "YES" at Step S14 and the procedure
goes to Step S15 for judgment whether the received code is the
manual code or not.
[0116] When the judgment is affirmative, the procedure advances to
Step S16 for executing the manual operation process. The received
code is not assumed now to be the manual code and it is thus judged
"NO" at Step S15. The procedure then moves to Step S17 where it is
examined whether the manual SW is turned on or not. When so, the
procedure returns back to Step S2. But it is now judged "NO" and
the procedure goes to Step S18 for initiating the welcome process
shown in FIG. 9.
[0117] In the welcome process, "YES" at Step S171 and "NO" at Step
S174 are provided and the procedure jumps to Step S180. As "NO" is
also given at Step S180, it is examined at Step S188 whether the
BLTM flag is 1 or not. At the time, the BLTM flag is not 1 and
procedure moves to Step S189 where the BLTM flag is shifted to 1 to
select the transmission of the B large response demand signal. Then
at Step S190, the variable n is set to 1. While only the A code is
received from the entry key, the above steps are repeated
(excepting that because "YES" is given at Step S188, Steps S189 and
S190 are skipped). The A response demand signal and the B large
response demand signal are thus transmitted at their respective
intervals of time.
[0118] As the driver steps closer to the vehicle, the entry key is
enabled to receive the B large response demand signal from the
vehicle and send back the B code. When the B code is received by
the vehicle, it is judged "NO" at Step S171 but "YES" at Step S201.
Accordingly, the door is unlocked at Step S204. As the A code has
been received at that time, "YES" is given at Step S209 and the
transmission of the I response demand signal is inhibited at Step
S212. At next Step S214, the BCHG flag is shifted to 0 to inhibit
the switching of the response demand signal from the B large to the
B small.
[0119] As the driver opens the door, steps in the vehicle, and
closes the door, it is judged "YES" at Step S6 (FIG. 4). Then, the
timer interruption permitting bit for permitting the transmission
of the I response demand signal is enabled at Step S8 to permit the
timer interrupted intermittent transmission of the I response
demand signal. At the time, the entry key is disabled to receive
the A and B response demand signals (which are transmitted to only
the outside of the vehicle) and hence, none of the A code and the B
code are received by the vehicle.
[0120] The entry key 50 receives the I response demand signal and
responds to send back the I code. When the I code is received by
the vehicle, the procedure runs through Steps S14, S15, and S17 and
enters at Step S18 the welcome process shown in FIG. 9. As it is
judged "NO" at both Steps S171 and 201, the procedure advances to
Step S221 shown in FIG. 10. A block denoted by the chained line SC
in FIG. 10 is a known immobilizing process.
[0121] It is examined at Step S221 whether the IMDONE flag
indicating the completion of the immobilizing checkup is 1 or not.
At the time, the immobilizing checkup is not executed and the
procedure goes to Step S222 for executing the immobilizing checkup.
In the immobilizing checkup, the I code received is examined
whether it is valid or not as will be explained later referring to
FIG. 11. When so, the IMOK flag is turned to 1. Step S223 follows
where the immobilizing checkup result is examined based on the IMOK
flag whether or not it is all right.
[0122] When it is judged "NO" at Step S223, the operation of the
engine is disabled at Step S227. When it is "YES", the procedure
goes to Step S224 for permitting the start of the engine. At Step
S225, the ATM flag is shifted to 0 and at Step S226, the AREC flag
is shifted to 0. In the next cycle of receiving the I code, it is
judged "YES" at Step S221. The procedure then moves to Step S228
where the timer interruption permitting bit for the I response
demand signal is cleared off to prohibit the intermittent
transmission of the I response demand signal.
[0123] The bit information of the IMOK flag is transferred via the
communication line (bus) 32 to the FI-ECU 33 (See FIG. 1). In
response to the bit of the IMOK flag, the FI-ECU 33 controls the
action of a fuel pump, a fuel injector, a fuel feeder, and an
ignition device (each not shown) in any known manner so that when
the bit is 1, the engine is enabled and while when 0, the engine is
disabled.
[0124] The blocks enclosed with the chain line SB in FIG. 9 are
provided for assigning different levels of hysteresis to the
communication area for the B response demand signals at the
embarkation and the disembarkation, and selecting the B small
response demand signal when the driver gets away from the vehicle
for permitting the door locking at earlier timing and while the B
large response demand signal when the driver approaches towards the
vehicle for permitting the door unlocking at possibly earlier
timing. It would hence be appreciated that when the hysteresis is
not applied, the blocks for switching between the B small signal
and the B large signal is unnecessary.
[0125] When the driver embarks and the IGN SW is turned on, it is
judged "YES" at Step S2 in FIG. 4 and the procedure moves to Step
S21 where are fresh 2 process for initializing the welcome function
flags is executed as will be explained lately in more detail
referring to FIG. 8. It is then examined at Step S22 whether the
IMOK flag is 1 or not (i.e. the result of the immobilizing checkup
is all right or not).
[0126] If it is judged "NO" at Step S22, the procedure goes to Step
S24 for disabling the operation of the engine.
[0127] It is then examined at Step S25 whether the IMDONE flag is 1
or not (i.e. the immobilizing checkup is finished or not). When
judged "NO", the procedure moves to Step S26 where the timer
interruption permitting bit for permitting the transmission of the
I response demand signal is enabled similar to Step S8. Then, the
immobilizing checkup process explained later in conjunction with
FIG. 11 is executed at Step S27. The procedure goes from Step S2 to
Step S22 thereafter. In the immobilizing checkup process, when the
immobilizing code received by the vehicle is qualified to be judged
that its key operation is correct, the IMOK flag is shifted to 1.
It is hence judged "YES" at Step S22.
[0128] By now, the checkup is right and the procedure advances to
Step S23 for enabling the start of the engine. As the IMDONE flag
is set to 1 in the immoblizing checkup process mentioned above,
"YES" is given at Step S25. The procedure then goes to Step S28
where the timer interruption permitting bit for the I response
demand signal is cleared off to prohibit the transmission of the I
response demand signal. During the running of the vehicle, the IGN
SW remains turned on, the above steps are repeated.
[0129] When the IGN SW is turned to the ACC or OFF position to stop
the engine, it is judged "NO" at Step S2. The procedure then moves
to Step S3 for executing the above described process at the
disembarkation.
[0130] The transmission of the response demand signals in the
welcome process will be explained referring to FIG. 6. This process
is executed in every x seconds by the timer interruption to
intermittently transmit the A or B (B large or B small) response
demand signal, provided that the response demand signal
transmission selecting flag is 1. The A, B large, and B small
response demand signals may be selected as previously described
referring to FIGS. 2, 3, and 13.
[0131] The procedure starts with Step S91 for examining whether
MOD(n,3) is zero or not. MOD(n,3) is the remainder of the variable
n divided by 3, which n is described previously concerning with
Steps S190 and S211. When MOD(n,3) is zero, the procedure goes to
Step S92 where it is examined whether the ATM flag is 1 or not.
When so, the procedure goes to Step S93 for permitting the
transmission of the A response demand signal.
[0132] When the remainder of n/3 is 1 or 2, it is judged "NO" at
Steps S91 or S92 and the procedure moves to Step S94 where the BTSM
flag is examined whether it is 1 or not. When so, the procedure
goes to Step S95 for permitting the transmission of the B small
response demand signal. When judged "NO" at Step S94, the procedure
moves to Steps S96 for examining whether the BLTM flag is 1 or not.
When so, the procedure advances to Step S97 for permitting the
transmission of the B large response demand signal.
[0133] The refresh 1 process at Step S3 (FIG. 4) will now be
explained referring to FIG. 7. At Step S101, the RF1 (refresh 1)
flag is examined whether or not it is 1 as indicating that the
refresh 1 process is completed. When judges "YES", i.e. the refresh
1 process is completed, the procedure jumps to EXIT. In the
beginning, it is judged "NO". At next Step S103, the IMOK flag is
shifted to 0 and at Step S104, the IMDONE flag (immobilizing
checkup is done) is shifted to 0. At Step S105, the IMCHK flag
(immobilizing checkup is started) is reset to 0.
[0134] As the result, the initialization of the immobilizing
checkup flags is completed. At Step S109, the RF1 flag is turned to
1 to register that the refresh 1 process has been done. At Step
S110, the RF2 flag is turned to 0 to register that the refresh 2
process is not yet done.
[0135] The refresh 2 process at Step S21 (FIG. 4) will be explained
in more detail referring to FIG. 8. At Step S121, the RF2 flag is
examined whether it is 1 or not, i.e. the refresh 2 process has
been done or not. When "YES", the procedure jumps to EXIT. When
judged "NO", the procedure runs through Steps S122, S123, and S124
for resetting the ATM, BLTM, and BSTM flags to 0, respectively.
Those steps are to inhibit the transmission of the A, B large, and
B small response demand signals, respectively.
[0136] This is followed by Steps S125 and S126 for resetting the
AREC and BREC flags to 0, respectively. These two steps are
provided for registering that the code, which is included in a
response signal send back from the entry key 50 in response to the
reception of the demand signal transmitted from the vehicle, is not
yet received by the receiver on the vehicle. At Step S128, the
variable n for determining the response demand signal to be
transmitted is turned to zero.
[0137] At Step S129, the OUT flag is shifted to 0 (denied) for
indicating that the entry key 50 is out of the communication area
of the A response demand signal. At Step S130, the RCHK flag is set
to 0 to indicate that the T-OUT timer is not started which sets the
limited time for detecting whether or not the entry key 50 is out
of the communication area for the A response demand signal. At Step
S131, the timer interruption permitting bit for the response demand
signal is cleared off to inhibit the timer interrupted
transmission.
[0138] After the above steps, the initialization of the welcome
function flags are completed. Then, Step S135 follows where the RF2
flag is turned to 1 to register the completion of the refresh 2
process. At Step S136, the RF1 flag is reset to 0 for registering
the non-completion of the refresh 1 process.
[0139] The immobilizing checkup process at Step S222 (FIG. 10) will
be explained in more detail referring to FIG. 11. The immobilizing
checkup process starts with Step S230 for examining whether the
IMCHK flag for indicating the starting of the immobilizing checkup
process is 1 or not. When the immobilizing checkup process is not
started and "NO" is given, the procedure moves to Step S235 for
setting the immobilizing checkup timer T-IMCHK to a desired
immobilizing checkup period (for example, 30 seconds). At Step
S236, the IMCHK flag is shifted to 1.
[0140] When the immobilizing checkup process has been started and
it is judged "YES" at Step S230, the procedure advances to Step
S231 for examining whether or not the immobilizing code I sent back
from the entry key is identical to the code previously saved in a
memory on the vehicle. When so, the procedure goes to Step S232
where the IMOK flag is turned to 1 to indicate the confirmation of
the immobilizing code comparison and Step S233 follows. Those steps
allow the FI-ECU 33 to positively control the operation of the
engine as described previously.
[0141] When judged "NO" at Step S231, the procedure goes to Step
S246 for examining whether the IMCHK timer is timed up or not. When
not, the immobilizing checkup process is terminated. When judged
"YES" at Step S246, the procedure goes to Step S233. At Step S233,
the IMDONE flag indicating that the immobilizing checkup process
has been done is turned to 1.
[0142] FIG. 12 illustrates the intermittent transmission of the I
response demand signal with the timer interruption permitting bit
for the I response demand signal being enabled, where the timer
interruption may be carried out in every z seconds. The procedure
starts with Step S271 for examining based on the IMDONE flag
whether the immobilizing checkup process is done or not. If not,
the procedure goes to Step S272 for permitting the transmission of
the I response demand signal. When the immobilizing checkup process
has been done and it is judged "YES" at Step S271, the procedure is
terminated.
[0143] According to the embodiment mentioned above, only when the
entry key sends back a signal in response to reception of the A
response demand signal transmitted from the vehicle at longer
intervals in the wider communication area, and the signal thus sent
back is received by the receiver on the vehicle and confirmed to be
correct response signal through the welcome code examination, the B
response demand signal for the smaller communication area is
transmitted at least once in the period of transmitting two of the
A response demand signals. In other words, even if any other person
or object not carrying the entry key and unrelated to the vehicle
moves into the A (response demand signal communication) area shown
in FIG. 13, the transmission of the B response demand signal is not
executed.
[0144] Accordingly, the occasion of transmitting the B response
demand signal for actually controlling the unlocking and locking
action of the door is minimized, hence decreasing the power
consumption of the vehicle battery. Also, the interval between
transmitting timings of two response demand signals is
significantly minimized, thus allowing the position of the entry
key relative to the vehicle to be more accurately identified. As a
result, the transmission of the B response demand signal at
intervals of an optimum period and in an optimum or relatively
smaller size of the communication area can be executed without
largely increasing the power consumption thus to precisely control
the vehicle mounted components, for example, the automatic
unlocking and locking action of the door of the vehicle,
corresponding to the distance between the entry key and the
vehicle. More particularly, the precise control over the vehicle
mounted components with the entry key can successfully be conducted
in compatibility with the favorable energy saving.
[0145] The foregoing embodiment is based on the use of the B
response demand signals common to all the doors of a vehicle in
conjunction with their response signals. In that case, it may
happen that when the entry key steps in such a predetermined
communication area as denoted by the B (large) in FIG. 13, all the
doors are unlocked at same time.
[0146] For avoiding such an event, an alternative embodiment is
provided as shown in the schematic view of FIG. 14 where three
different B response demand signals B1, B2, and B3 respectively
assigned to two of left and right doors 2a, 2b and a rear trunk
door 2c are provided. For example, when any one of the three B
response demand signals is not received, all the doors are locked
simultaneously. On the other hand, desired one of the doors can be
unlocked by the controlling action of a vehicle mounted receiver
which receives a B code for the desired door included in a response
signal to the B response demand signal assigned to the desired
door.
[0147] It should be understood by those skilled in the art that for
applying the B response demand signals assigned to their respective
doors, Step S201 in the flowchart of the welcome process shown in
FIG. 9 may be modified to examine the received code for its
matching with an unique code assigned to the desired door. Hence,
the modification of the flowchart will be explained in no more
detail. It is also appreciated that different levels of the
hysteresis may be allocated to the sizes of the communication areas
between the unlock and lock operation.
[0148] FIG. 15 illustrates an exemplary format of the response
signal applicable to the above- and under-mentioned embodiments of
the present invention. As shown, CDA is a start bit, CDB is an
identification code, CDID is an ID code uniquely assigned to each
vehicle, and CDF is a function code. The figures in the parenthesis
represent the numbers of bits of the codes. In general, the ID code
is used for examining if an entry key is authentic, while the
function code is for discriminating the A and B codes from each
other. The function code may be comprised of four bits,
respectively; for example, the A code is [1000], the B code [1001],
the manual lock code [1100], and the manual unlock code [1101],
respectively in the case of FIG. 13, while the A code is [1000],
the B code for the driver's door [1001],the B code for the
passenger's door [1010], and the B code for the trunk door [1011]
in the case of FIG. 14.
[0149] FIG. 16 illustrates an exemplary format of the response
signal for the (anti-thief) immobilizing function applicable to the
embodiments of the present invention. As the code comparison for
the immobilizing function is extremely important for ensuring the
anti-thief action as well known, it may preferably be
differentiated in the structure from the other codes. As shown, CDA
is a start bit, CDB is an identification code, and CDIM is an
immobilizing function ID code. It is also possible to have all
types of the response signals designed to a single particularly
structured format.
[0150] Although the hysteresis characteristic is assigned to the
communication areas for the B response demand signal between the
unlock mode and the lock mode, the present invention is not limited
to always have the hysteresis characteristics. The B large response
demand signal and the B small response demand signal shown in the
schematic view of FIG. 13 and the timing charts of FIGS. 2 and 3
may be a single and common B response demand signal.
[0151] As for a further embodiment of the present invention using
the single and common B response demand signal, a flowchart of its
main procedure (corresponding to FIGS. 4 and 5) is shown in FIGS.
17 and 18 while a flowchart of its welcome function process
(corresponding to FIG. 9) is shown in FIG. 19. Throughout the
figures, like components are denoted by like numerals as those
shown in FIGS. 4, 5, and 9 and will be explained in no more detail
but only different steps or blocks will be explained below.
[0152] At Step S12B in FIG. 17, the B response demand signal
selecting flag BTM is shifted to 1 for enabling the timer
interrupted transmission of the B response demand signal. At Step
S38B in FIG. 18, the flag BTM is reset to 0 to inhibit the
transmission of the B response demand signal. Step S186B in FIG. 19
is provided for examining whether the flag BTM is 0 or not. The
flag BTM is turned to 1 at Step S188B to permit the transmission of
the B response demand signal, preparing for unlocking of the door
as the driver comes towards the vehicle. When the entry key departs
further from the vehicle and it is disabled to receive even the A
response demand signal, the intermittent transmission of the A
response demand signal only is maintained as described with the
previous embodiment.
[0153] As the entry key 50 comes close to the vehicle, it receives
the A response demand signal and sends back the A code. When the A
code is received by the vehicle mounted receiver, it is judged
"YES" at Step S171, "NO" at Step S174, and "YES" at Step S186B
similar to those of the previous embodiment. Accordingly, Step
S188B permits the transmission of the B response demand signal. The
succeeding procedure may clearly be understood from the forgoing
descriptions.
[0154] FIG. 20 is a flowchart showing the timer interrupted
transmission of the A and B response demand signals executed in the
welcome process of this embodiment. This drawing is similar to FIG.
6 in which like blocks are denoted by like numerals as those shown
in FIG. 6 and they will be explained in no more detail. It is
examined at Step S91B whether MOD(n, 2) which is the remainder of
n/2 is zero or not (i.e. n is an odd number or an even number).
When judged "NO" or n is an odd number, the procedure goes to Step
S94B for examining whether the flag BTM for permitting the timer
interrupted transmission of the B response demand signal is shifted
to 1 or not.
[0155] When so, the transmission of the B response demand signal is
permitted at Step S95B and procedure moves to Step S98. When it is
judged"NO" at Step S94B, n is updated at Step S98 before the
procedure of this process is terminated. The divisor such as 2 or 3
used at Steps S91B and S91 may preferably be determined so that the
transmission of the response demand signals is timed favorably with
the interval of the timer interruption settings (x or x'
seconds).
[0156] Although the response demand signal transmitted from the
vehicle mounted receiver is classified into two different types, A
and B, for the wider and the narrower communication areas
respectively in the previous embodiments, the prevent invention may
employ three or more types of the response demand signals for
different sized communication areas. FIGS. 21A and 21B are timing
charts illustrating the transmission of three different types of
the response demand signal.
[0157] As shown, while the A response demand signal for the widest
communication area is transmitted at intervals of the longest
period y, the B response demand signal for the second widest
communication area is transmitted, for example, at every
intermediate moment between two adjacent transmitting timings of
the A response demand signal, provided that the A code is received
by the vehicle, indicating that the A response demand signal is
successfully received by the entry key which is moving towards the
vehicle.
[0158] The C response demand signal for the smallest communication
area is also transmitted at every intermediate moment between the A
response demand signal and the B response demand signal, provided
that the B code is received indicating that the B response demand
signal is successfully received by the entry key which is moving
towards the vehicle. Those codes in the response signals may be
expressed as, for example, the A code [1000], the B code [1001],
the C code [1011] and the I code [0101].
[0159] On the other hand, when the driver disembarks and the entry
key departs from the vehicle, the response signal responding to the
C response demand signal for the smallest communication area will
first become impossible of being received, then the response signal
to the B response demand signal for the medium sized communication
area, and finally the response signal to the A response demand
signal for the widest communication area. The interval between two
adjacent receptions of the response signals will thus be increased
step by step.
[0160] In this embodiment, the response signal carrying the
response code (one of the A, B, and C codes) is send back from the
portable transmitter/receiver of the entry key corresponding to
which one of the response demand signals for the communication
areas of different sizes is received by it, hence allowing the
control unit on the vehicle to intimately identify the location of
the entry key relative to the vehicle. Accordingly, the vehicle
mounted components can favorably be controlled depending on the
distance from the vehicle to the entry key determined on the basis
of the code in the response signal sent back.
[0161] As will be understood from the timing chart of FIGS. 21A and
21B, the response codes are received at intervals of a shorter
period or at a higher rate of frequency from the entry key which is
in a position closer to the vehicle. The location of the entry key
relative to the vehicle can thus be identified by measuring the
receiving cycle or frequency of the response codes on the vehicle.
Also, as the entry key is in the position closer to the vehicle,
the receiving cycle will be expected to be shorter thus possibly
making the response action of the vehicle mounted components
quicker.
[0162] Although the above-mentioned embodiments include
transmitting from the vehicle mounted transmitter different types
of the response demand signals which are different in the size of
the communication area and the characteristics, sending back from
the entry key the response codes corresponding to the type or the
communication area of the response demand signal received, and
identifying on the basis of the received response code the location
of the entry key relative to the vehicle, the different types of
the response demand signals may be designed uniformly in the
characteristics and their response codes for simplification of the
signal structure, when they are transmitted from the vehicle
mounted transmitter at their respective frequencies or repetitive
cycles different each other in their corresponding sizes of the
communication areas as shown in FIGS. 21A and 21B.
[0163] Subsequently, the distance of the entry key from the vehicle
can successfully be identified from the receiving intervals, the
frequencies, or repetitive cycles of the response signal (response
code) received by the vehicle mounted receiver and used for
favorably controlling the operation of the vehicle mounted
components according to the distance identified. An embodiment of
the above modification will now be described referring to FIGS. 22
and 23. In these two graphs, the height of the different types of
the response demand signals WS and WL represents only the intensity
of the signal which is the size of the corresponding communication
area.
[0164] FIG. 22 is a time chart showing schematically the actions
when the driver carrying the entry key disembarks and walks away
from the vehicle. As the vehicle 1 stops, the IGN SW is turned at
t1 from the ON position to the ACC position and the door is opened
at t2 by the driver for disembarkation. Then, the door SW is
shifted from the OFF (open) position to the ON (close) position.
This triggers the transmission of the W small response demand
signal WS for a narrow communication area. The W small response
demand signal WS is transmitted from the vehicle mounted
transmitter at the predetermined intervals of 2u.
[0165] When the entry key 50 steps out from the vehicle and is
enabled to receive the W small response demand signal WS, it
releases a response signal carrying the W code (referred to as W
code hereinafter) As the W code is received and the welcome code
comparison is confirmed at t3, a first timer TWR1 for the receiving
interval is set to a period v and then initiated. Simultaneously,
the intermittent transmission of the W large response demand signal
WL is initiated, of which the communication area is greater than
that of the W small response demand signal (i.e. the transmitting
output is higher while the other characteristics are identical to
WL).
[0166] In this embodiment, the W large response demand signal WL is
transmitted at every intermediate moment between two transmitting
timings of the W small response demand signal WL and hence at the
intervals equal to 2u seconds as illustrated. The setting time v of
the timer may preferably be equal to the minimum transmitting
interval (u) between the adjacent two response demand signals WS
and WL.
[0167] This setting is preferable but not necessary. It is simply
required to transmit the two response demand signals WS and WL
alternately and more generally, to clearly discriminate the
difference between an interval of transmitting timings when only
the W large response demand signal WL is transmitted and the other
interval when both of the W large and small response demand signal
WL and WS are transmitted (preferably, the latter is shorter). In
practice, the setting time v may preferably be set to (u+.DELTA.u)
seconds considering various unevenness in the system.
[0168] As the welcome code comparison is confirmed at t4 with the W
code received, a second timer TWR2 for the receiving interval is
set to v and initiated. Simultaneously, it is examined whether the
first timer TWR1 is timed up or not. As apparent from the criteria
for setting the two timers, the two timers are not timed up while
the W large and small response demand signal WL and WS are
successfully received by the entry key which in turn releases their
corresponding response signals W.
[0169] As the entry key 50 departs further from the vehicle and
receives no more the W small signal WS, the vehicle mounted
receiver is disabled to receive its response signal. One of the
timers TWR (namely, the second timer TWR2 in this case) is then
timed up to be turned to zero at t5. As the W code responding to
the W large response demand signal is received and the welcome code
comparison is confirmed at t6, the first timer TWR1 is restarted
and the time up of the second timer TWR2 is acknowledged.
[0170] It is hence determined that the receiving interval of the W
code is longer than v, i.e. the entry key is out of the
communication area of the W small response demand signal WS,
allowing the door of the vehicle to be locked. When the W code is
not received within m seconds of the preset time after the locking
action, the transmission of the W small response demand signal WS
is stopped and the intermittent transmission of only the W large
response demand signal WL is continued.
[0171] Referring to FIG. 23, the actions when the driver comes
towards the vehicle 1 and its location is detected will be
explained. When the entry key is out of and significantly distanced
from the vehicle with the door locked in its disembarkation or
parking mode, the W large response demand signal WL for the wider
communication area is being transmitted at the predetermined
intervals (of 2u seconds) from the vehicle as described previously
and shown at the left most portion in FIG. 23. As the driver
carrying the entry key steps into the communication area of the W
large response demand signal WL about the vehicle, the entry key
receives the W large response demand signal WL at t1.
[0172] Then, the entry key send back the W code responding to the
reception of the W large response demand signal WL. As the W code
is received by the vehicle and determined at t2 by the welcome code
comparison that it is valid, the vehicle mounted control unit
starts the first timer TWR1 for the receiving interval and
simultaneously transmits the W small response demand signal WS at
the equal interval (of 2u) and at every intermediate moment between
two adjacent transmitting timings of the W large response demand
signal WL.
[0173] When the W code which is released from the entry key
responding to reception of the W large response demand signal at t3
prior to the reception of the W small response demand signal WS is
received and judged by the welcome code comparison that it is
valid, the second timer TWR 2 for the receiving interval is
started. At the time, the first timer TWR1 is timed up and the door
is not unlocked.
[0174] As the entry key 50 comes close enough to receive the W
small response demand signal WS, it releases the corresponding W
code. Upon the W code received and judged that it is valid, the
second timer TWR2 is started at t4 and it is determined that the
first timer TWRL is not timed up. Then, the door of the vehicle is
unlocked. When the door is opened (the door SW turned on) and then
closed at t5, it is determined that the driver is in the vehicle.
Then, the transmission of the I (immobilizing) response demand
signal is initiated for its communication area limited within the
vehicle (not shown in FIG. 23).
[0175] As the entry key releases the immobilizing code (I code) in
response to the I response demand signal, the immobilizing code is
received and examined by the vehicle. When it is judged that the I
code is valid, the transmission of the I response demand signal is
stopped thus enabling the start of the engine. As the ignition SW
is turned to the ON position at t6, the transmission of both the
response demand signals WL and WS is stopped and simultaneously the
refresh 2 process is initiated as will be explained later.
[0176] The transmission of the response demand signals WL and WS
may be stopped when it is judged that the I code is valid. The
response demand signal is not limited to the two types, WL and WS,
and may be classified into three or more types which are different
from each other in the size of the communication area and the
transmitting interval.
[0177] A detailed procedure of this embodiment will now be
described referring to its main flowcharts of FIGS. 24 and 25 and
its welcome process flowchart of FIG. 26. In these drawings, the
contents of process in blocks denoted by same numerals are
identical to those in FIGS. 4, 5, and 9 and will be explained in no
more detail but their different aspects.
[0178] Referring to FIG. 24, when the driver opens the door for
disembarkation, the procedure goes from Step S10 to Step S11W for
examining whether the WREC flag is 1 or not, i.e. the W code is
received or not from the entry key 50. At the disembarkation, this
step judges "NO" and the WSTM flag is turned to 1 at Step S12W to
select the transmission of the W small response demand signal WS.
Step S13 follows for enabling the intermittent transmission of the
W small response demand signal WS with timer interruption.
[0179] The timer interruption for the intermittent transmission is
carried out at the interval of u seconds as clearly illustrated in
FIGS. 22 and 23. More specifically, the A and B response demand
signals in the flowchart of FIG. 20 are replaced with the W large
and W small response demand signals WL, WS, respectively. As the
driver or the entry key steps out from the vehicle and receives the
W small response demand signal, it sends back the W code in
response. The W code is then received by the vehicle mounted
receiver allowing Step S14 to judge "YES" and the welcome process
at Step S18 follows.
[0180] FIG. 26 illustrates the flowchart of the welcome process
which is to be combined with FIG. 10. The operation is first
explained when the driver disembarks and its entry key departs from
the vehicle. As the W code transmitted from the entry key
responding to the reception of the W small response demand signal
WS from the vehicle is received by the vehicle, it is judged "YES"
at Step S301 and the procedure goes to Step S302. If it is judged
"NO", the procedure jumps to Step S221 in FIG. 10. At Step S302,
the WREC flag indicating the reception of the W code is shifted to
1.
[0181] This is followed by a sequence of Steps S303 to S306 for
updating by one the count of the W counter which represents the
number of receptions of the W code (the count incremented to 1 by
the first reception), shifting the WLTM flag to 1 for selecting the
transmission of the W large response demand signal, turning the OUT
flag to 0 for registering that the entry key is within the
communication area of the W large response demand signal WL, and
resetting the timer TOUT setting time for detecting that the entry
key is no more close to the vehicle, respectively.
[0182] Then, it is examined at Step S307 whether the count of the W
counter is 1 or not. As the count is 1 and judged "YES" by now, the
procedure advances to Step S308 for setting and initiating the
first timer for the receiving interval with the time v and then
returns back to Step S2 in FIG. 24. At the next cycle of receiving
the W code, Steps S307 judges "NO" and the procedure goes to Step
S309 where it is examined whether the remainder of the count of the
W counter divided by 2 is 0 or not, i.e. whether the count of the W
counter is an odd number or an even number.
[0183] As the count is 2 and it is judged "YES", the second timer
TWR2 is equally set to v and initiated at Step S310. Then, Step
S311 follows for examining whether the first timer TWR1 is counted
up or not. As described previously referring with FIG. 22, the W
codes are continuously released in response to the W large and
small response demand signals WL and WS for a while after the
disembarkation and can thus be received before the timers are timed
up. Accordingly, Step S311 judge "NO".
[0184] Therefore, the procedure advances to Step S312 for
maintaining the unlocked state of the door. When the reception of
the next W code increases the count of the W counter to 3, the
procedure goes from Step S309 to Step S314 for setting and
initiating the first timer TWR1 with the time v. It is then
examined at Step S315 whether the second timer TWR2 is counted up
or not.
[0185] While the entry key departs not far enough from the vehicle,
Step S315 judges "NO" as described above and the unlocked state of
the door is maintained at Step S312. When the entry key departs far
enough from the vehicle and is disabled to receive the W small
response demand signal WS, it is then judged "YES" at Step S315 and
the procedure goes to Step S316 where the door of the vehicle is
locked. Also, when Step S311 judges "YES" upon an even number of
receiving times of the W code, the door is locked at Step S318.
[0186] As the entry key 50 departs further from the vehicle, it is
disabled to receive the W large response demand signal WL and fails
to deliver the corresponding W code to the vehicle. It is then
judged "NO" at Step S14 in FIG. 24 and the procedure goes from
Steps S15A and S30 to Step S35. At the time, Step S35 judges "YES"
and the initialization is executed at Steps S36W to S39W and S40.
More particularly, the W counter is reset to zero, the first timer
TWR1 and the second timer TWR2 are reset, the WSTM flag is turned
to 0, and the OUT flag is shifted to 1.
[0187] The action of automatically unlocking the door will now be
explained when the driver carrying the entry key 50 moves towards
the vehicle for embarkation. As the entry key 50 steps into the
communication area of the W large response demand signal WL and
receives the signal WL, it releases the corresponding W code. When
the W code is received for the first time and judged at Step S301
in FIG. 26 that it is valid, the same process at Steps S302 to S307
are repeated.
[0188] More specifically, the W counter is reset to 1, the WLTM
flag is shift to 1, the OUT flag is shifted to 0 for registering
that the entry key is within the communication area, and the timer
T-OUT is reset. At the time, Step S307 judges "YES" and the first
timer TWR1 is set to v at Step S308 before the welcome process is
terminated.
[0189] As the reception of the next W code causes Step S307 to
judge "NO" and Step S309 to judge "YES", the second timer for the
receiving interval TWR2 is set with v at Step S310. Step S311
follows where it is judged "YES" because the entry key 50 receives
only the W large response demand signal WL and the interval of the
W code is long enough, hence maintaining the locked state of the
door.
[0190] Also, when the procedure goes from Step S309 to Steps S314
and 315, the locked state of the door is maintained at Step S316.
As the entry key comes closer to the vehicle and receives too the W
small response demand signal WS, Step S311 or S315 judges "NO"
permitting the door to be unlocked.
[0191] When the driver opens the door, steps into the vehicle, and
shuts up the door, it is then judged "YES" at Step S6 (FIG. 24) and
the timer interrupted transmission of the I response demand signal
is enabled at Step S8. As described with the first embodiment, when
the I code comparison is confirmed, the action of the engine is
enabled. As the ignition switch IGN SW is turned by the driver to
the ON position, the engine starts running and simultaneously, the
transmission of the W response demand signals and the I response
demand signal is stopped. Then, the flags are initialized at the
steps in Block S41 (FIG. 25).
[0192] According to this embodiment, while the two types, WL and
WS, of the response demand signal can successfully be switched from
one to another by changing only the output level of the response
demand signal from the vehicle mounted transmitter, the response
code released from the entry key is used only of one type, W code.
Therefore, the transmitter and receiver arrangements as well as the
code identification function will significantly be simplified, thus
contributing to the lower cost and the ease of maintenance.
[0193] Although both the unlocking and locking actions of the door
are automatically controlled according to the reception of response
signal to the response demand signals on the vehicle mounted
receiver in the embodiments mentioned above, it will clearly be
understood by those skilled in the art to automate only one of the
two actions for more simplicity.
[0194] According to the present invention recited in claims 1 and
2, the distance from the vehicle to the user carrying the portable
transmitter/receiver (entry key) can precisely be identified thus
to control the vehicle mounted device such as the door(s) at an
optimum length of the distance, hence improving the utility of
controlling the vehicle mounted device such as unlocking and
locking the door(s) is compatible with improvement in the
anti-thief function.
[0195] According to the present invention recited in claim 3, the
distance from the vehicle to the user carrying the portable
transmitter/receiver can be identified on the basis of the interval
between receiving timings of the sent-back response signal on the
vehicle even if the characteristic codes included in the response
signals are not different each other, which response signals are
sent back from the portable transmitter/receiver in response to a
plurality kinds of the response demand signal receivable within
their respective sizes of the predetermined ranges which are
different each other. Hence, the vehicle mounted device can
favorably be controlled depending on the distance as well as the
construction of the transmitter of the portable
transmitter/receiver and the code identifying action of the
controlling means on the vehicle can significantly be
simplified.
[0196] According to the present invention recited in claim 4, the
response signal is also released at intervals of time from the
portable transmitter/receiver, thus providing the same effects and
advantages as described just above relating to the claim 3
invention.
[0197] According to the present invention recited in claim 5, as
the response signals released from the portable
transmitter/receiver in response to reception of the response
demand signal are different each other based on the different sizes
of the receivable ranges of the demand signals, the distance from
the vehicle to the portable transmitter/receiver can be identified
only from the response signal received and the optimum control of
the device mounted on the vehicle can be performed in accordance
with the distance.
[0198] According to the present invention recited in claims 6 and
7, at the disembarkation of the user, as the portable
transmitter/receiver carried by the user departs far from the
vehicle, the transmission of the response demand signal receivable
in a predetermined wider size of the range is executed, while the
transmission of the response demand signal receivable in a
predetermined smaller size of the range is canceled. As the potable
transmitter/receiver comes from far towards the vehicle, on the
other hand, the transmission of the response demand signal with a
smaller predetermined receivable range is not executed before the
response signal responding to the response demand signal with the
largest predetermined receivable range is received by the
vehicle.
[0199] More particularly, while the portable transmitter/receiver
is out of the largest predetermined receivable range, the response
demand signal receivable in the largest predetermined range only is
transmitted. Only when the response signal responding to the
response demand signal receivable in the largest predetermined
range is received by the vehicle, the transmission of the response
demand signal receivable in a smaller size of the predetermine
range and used for actually controlling the unlocking and locking
of the door is executed. Therefore, the transmission of the
response demand signal is minimized hence reducing the consumption
of a power from a battery equipped on the vehicle.
[0200] According to the present invention recited in claim 8, the
user carrying the portable transmitter/receiver in the vehicle can
precisely be acknowledged, and the vehicle mounted device in the
vehicle is controlled on the basis of the response signal from the
portable transmitter/receiver responding to a particular type of
the response demand signal receivable within the vehicle, hence
improving the anti-thief function.
[0201] In brief, the present invention allows the entry key to
receive the response demand signal for a wider communication area
and send back a response signal to the vehicle, and the vehicle to
transmit the response demand signal for a smaller communication
area only when the response signal from the entry key is examined
and qualified to be valid by its welcome code comparison. In other
words, even if any other person or object not relating to the
vehicle is within the communication area A shown in FIG. 13, no
transmission of the B response demand signal is permitted.
[0202] Accordingly, the transmission of the B response demand
signal for actually controlling the locking and unlocking action of
the door is minimized hence favorably reducing the consumption of a
power in the battery. Also, while the power consumption is
minimized, the transmission of the response demand signals can be
executed at optimum intervals of time for a relatively smaller size
of the communication area corresponding to the distance from the
entry key to the vehicle thus to precisely control the vehicle
mounted components, for example, automatically unlocking and
locking the door of the vehicle. More particularly, the control
over the vehicle mounted components with the entry key can be made
in compatibility with the energy saving. In practice, while the
power consumption is minimized, the anti-thief function can be
realized at higher utility.
[0203] Moreover, as different types of the response demand signals
are transmitted from the vehicle at intervals of time, the
transmission of the response demand signal for a wider
communication area is executed at intervals of a longer duration.
This permits the control system to readily acquire the distance
from the vehicle to the entry key on the basis of the interval
between receiving timings of the response signal from the entry key
without discriminating the response demand signals and the response
signals received, respectively, from each other and thus to
favorably control the vehicle mounted components such as doors.
Accordingly, the overall system can further be simplified in
construction and operation.
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